add: polls backend

TODO: polls frontend

crates/core/src/model/communities.rs

@@ -240,6 +240,8 @@ pub struct Post {
     pub uploads: Vec<usize>,
     /// If the post was deleted.
     pub is_deleted: bool,
+    /// The ID of the poll associated with this post. 0 means no poll is connected.
+    pub poll_id: usize,
 }
 
 impl Post {
@@ -249,6 +251,7 @@ impl Post {
         community: usize,
         replying_to: Option<usize>,
         owner: usize,
+        poll_id: usize,
     ) -> Self {
         Self {
             id: Snowflake::new().to_string().parse::<usize>().unwrap(),
@@ -263,12 +266,13 @@ impl Post {
             comment_count: 0,
             uploads: Vec::new(),
             is_deleted: false,
+            poll_id,
         }
     }
 
     /// Create a new [`Post`] (as a repost of the given `post_id`).
     pub fn repost(content: String, community: usize, owner: usize, post_id: usize) -> Self {
-        let mut post = Self::new(content, community, None, owner);
+        let mut post = Self::new(content, community, None, owner, 0);
 
         post.context.repost = Some(RepostContext {
             is_repost: false,
@@ -369,3 +373,107 @@ impl PostDraft {
         }
     }
 }
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct Poll {
+    pub id: usize,
+    pub owner: usize,
+    pub created: usize,
+    /// The number of milliseconds until this poll can no longer receive votes.
+    pub expires: usize,
+    // options
+    pub option_a: String,
+    pub option_b: String,
+    pub option_c: String,
+    pub option_d: String,
+    // votes
+    pub votes_a: usize,
+    pub votes_b: usize,
+    pub votes_c: usize,
+    pub votes_d: usize,
+}
+
+impl Poll {
+    /// Create a new [`Poll`].
+    pub fn new(
+        owner: usize,
+        expires: usize,
+        option_a: String,
+        option_b: String,
+        option_c: String,
+        option_d: String,
+    ) -> Self {
+        Self {
+            id: Snowflake::new().to_string().parse::<usize>().unwrap(),
+            owner,
+            created: unix_epoch_timestamp() as usize,
+            expires,
+            // options
+            option_a,
+            option_b,
+            option_c,
+            option_d,
+            // votes
+            votes_a: 0,
+            votes_b: 0,
+            votes_c: 0,
+            votes_d: 0,
+        }
+    }
+}
+
+/// Poll option (selectors) are stored in the database as numbers 0 to 3.
+///
+/// This enum allows us to convert from these numbers into letters.
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
+pub enum PollOption {
+    A,
+    B,
+    C,
+    D,
+}
+
+impl From<u8> for PollOption {
+    fn from(value: u8) -> Self {
+        match value {
+            0 => Self::A,
+            1 => Self::B,
+            2 => Self::C,
+            3 => Self::D,
+            _ => Self::A,
+        }
+    }
+}
+
+impl Into<u8> for PollOption {
+    fn into(self) -> u8 {
+        match self {
+            Self::A => 0,
+            Self::B => 1,
+            Self::C => 2,
+            Self::D => 3,
+        }
+    }
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct PollVote {
+    pub id: usize,
+    pub owner: usize,
+    pub created: usize,
+    pub poll_id: usize,
+    pub vote: PollOption,
+}
+
+impl PollVote {
+    /// Create a new [`PollVote`].
+    pub fn new(owner: usize, poll_id: usize, vote: PollOption) -> Self {
+        Self {
+            id: Snowflake::new().to_string().parse::<usize>().unwrap(),
+            owner,
+            created: unix_epoch_timestamp() as usize,
+            poll_id,
+            vote,
+        }
+    }
+}